Ceiling fans are often mounted in rooms to improve air circulation and/or provide cooling. In some cases lights are mounted on the fan. While the ability to separately control a fan motor and light are desirable, such control if implemented using standard wired switches requires separate switches for the light and the fan motor.
In many cases, fans are mounted where a ceiling light was previously located and thus while power, e.g., 120V, may be available at the location where the fan is being mounted connections to multiple switches may not be available. In such cases, the combined ceiling fan and light fixture may receive power via a single wall switch with the power being provided to both the light and fan motor at the same time. In order to allow separate control of the light and fan motor switches pull cords may be included in the fan assembly with one switch being used to control the light fixture and another being used to control the fan motor.
While the use of pull cord controls of a fan and light are common, they are not only unsightly but can pose potential safety issues. Dangling cords can accidently get caught on objects, people and/or even get entangled in the moving fan blades. With advancements in LED lighting it is often desirable to support variable lighting levels rather than a simple on/off light control. Similarly the ability to control the speed of a ceiling fan motor rather than simply turn the motor on and off can be desirable.
In the interest of energy efficiency it can be desirable to support fan and/or light control according to a schedule which takes into consideration calendared events, work schedules and/or other conditions so that a fan and/or light is not run needlessly when no one is around. To the extent that a schedule could be supported, it would be desirable if the schedule could be entered and implemented without the need for a wired wall controller to provide control signals via a wire to the fan and/or light unit since wires can be difficult and/or costly to run.
Additionally, known DC motor fan systems, e.g., fan systems using DC brushless motors, that are available experience problems when controlled over the same power run, e.g., when three fans are daisy chained together so that power is connected to a first fan and from the first fan to a second fan and then a third fan, the third fan typically does not operate properly it experiences being off kilter in time and speed on start up.
In view of the above it should be appreciated that there is a need for improved methods of controlling a fan and/or ceiling light. It would be desirable if at least some of the improved methods and/or apparatus could avoid the need for multiple wall switches wired separately to a fan and a light. While not necessary for all embodiments it would be desirable if fan and/or light control could support a wide range of functions such as fan speed, fan direction, and/or light intensity in addition to simple light and/or fan on/off operations.
In some cases in addition to being able to control a fan and/or light without the need for separate hardwired switches to the individual fan or light, it would be desirable if a safety shut off mechanism were supported. For example, it would be desirable if in at least some embodiments rather than relying on commands or controls to turn off a fan and/or light a safety mechanism was available to quickly disable the fan motor and/or light in the event of a safety concern. In at least some such cases it would be desirable if power to the fan and/or light unit could be fully cut off to quickly stop motor operation even in the event of erroneous control signals being sent to the fan and/or an error on a fan controller that is responsible for controlling the fan. In the case where a wall unit may include a controller which sends commands to one or more fan units it would be desirable if the safety mechanism could also disable the wall control unit's ability to send commands so that all portions of the fan system are reliably disabled.
In further view of the above, it should also be appreciated that there is a need new and/or improved fan systems that utilize DC motors, e.g., DC brushless motors, so that smooth control of fan operation in each of the DC motors can be achieved. Furthermore, there is a need for new and/or improved apparatus that can power and/or control DC brushless motors so as to provide smooth control of fan motor operation without use of an optical sensor, optical encoder, magnetic encoder, e.g., resolver or synchro, or Hall effect sensor in the motor control unit which add to the cost of the fan device and overall system.